Tag Archives: Stigmergy

Social relationships and groups: New insights on embodied and distributed cognition

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Eliot’s intro and first section to his paper:

Human cognition mostly takes place in the context of other people. This is true in two ways. First, if we consider the immediate context of other people who are physically present, they may influence or even help constitute an individual’s cognition by providing information, agreeing or disagreeing, being part of a group decision-making process, etc. (Tollefsen, 2006 and Wegner, 1986). And as a broader context, the group memberships and socially defined identities that make each of us who we are (e.g. an American, a professor, a father) both motivate and potentially bias our cognition as we move through our lives. As Clancey (1997, p. 366) put it, the “overarching content of thought is not…[descriptions or symbolic representations of states of the world], but coordination of an identity” in a social context. If I sit alone in my office working on a paper for publication, my actions are nevertheless socially shaped, for they ultimately reflect socially defined identities and goals (e.g. to write an interesting paper; to win the approval of professional colleagues; to be a successful researcher; to earn a living for myself and my family). Indeed, a pure case of individual (nonsocial) cognition – cognition that is independent not only from immediate social influences but also from the individual’s network of social relationships, group memberships, and self-identities – is difficult to even imagine.

The field of social psychology has as its defining focus such social influences on individual cognition, affect, and behavior, in both forms (the immediate social context, and the larger web of relationships and identities that shape the individual). Thus, this special issue on situated/embodied/distributed perspectives on social cognition addresses issues that are central to the field of social psychology. For this reason it is interesting to note that these emerging perspectives have actually been introduced to the field only recently (e.g. Barsalou et al., 2003, Semin and Smith, 2002, Semin and Smith, in press and Smith and Semin, 2004) – as much as a decade or two after they were initially advanced within artificial intelligence and cognitive science (Brooks, 1986/1999, Clancey, 1997 and Clark, 1997). However, as argued elsewhere in more detail (Smith & Semin, 2004), despite its recent onset, the integration of situated/embodied/distributed perspectives with the substantive concerns of social psychology is likely to be extraordinarily fruitful, even revolutionary in many respects. The reason is that the merger of these new perspectives, which have mostly been applied to improve our understanding of individual cognition and adaptive behavior, and the emphasis of social psychology on the centrality of the social context of behavior, opens up new vistas for conceptual and theoretical exploration.

This article addresses the intersection of embodied and distributed cognition, a focus that holds special interest from the viewpoint of social psychology. We can conceptualize this intersection in three ways. The first point is simply what these perspectives have in common: both seek to extend our conception of cognition beyond information processing performed by the brain, to include the body and sensory-motor systems (embodied cognition) as well as other bodies and minds (distributed cognition). Second, the principle of embodiment has to date been applied mostly to understanding individual functioning (e.g. the role of motor representations in language comprehension). Adding a distributed cognition perspective suggests that embodiment also has implications beyond the level of the individual, for example with regard to interpersonal cooperation or relationships. Third, socially distributed cognition, such as group problem-solving, has mostly been conceptualized as involving abstract, amodal information processing. But adding the embodiment perspective calls attention to potential embodied influences on group interaction and collective cognition. In fact, it can be argued that an important function of embodiment is to externalize cognitive processes so they can influence and be influenced by others. For example, if someone looks puzzled and scratches his head when trying without success to solve a puzzle or retrieve some information from memory, it may cue others to jump in and offer suggestions or help. If cognition was disembodied – implemented purely by inner computation processes lacking any external signs – distributing cognition across a group of people would be much more difficult.

This paper will discuss two areas within the intersection of the embodiment principle and distributed cognition. First, there are embodied aspects of social relationships as well as of individual-level cognition, and some preliminary evidence is now available on this point. Second, we will examine some general properties of socially distributed cognition (e.g. group problem-solving) in comparison to individual-level cognition. Research in this area has only begun to examine embodiment effects, but we will suggest some relevant possibilities.

1. Embodiment of social relationships

The principle of embodiment has typically been applied in an effort to understand individual-level functioning. For example, research addresses how the physical properties of muscles and limbs ease demands for neural control in locomotion (e.g. Thelen & Smith, 1994) or how multimodal representations of concepts enable language comprehension (e.g. Barsalou, 1999). A broader look at the embodiment concept includes examination of how aspects of social functioning – specifically, social relationships – are signaled and regulated by embodied cues.

The most directly relevant framework for addressing this topic is the relational models theory developed by Fiske (2004), a cognitive anthropologist. Fiske holds that there are four fundamental types of social relationships. Communal sharing (CS) describes a relationship where people focus on what they have in common and share resources as needed; it is typically found between close kin, and among members of cohesive groups, clans, etc. Authority ranking (AR) describes relationships structured by ordered differences in power or status; they are typically found in workplaces and other hierarchical social institutions, and also in many cases between parents and children. Two other types of relationships are argued to be historically more recent developments, and we will have little to say about these. Equality matching (EM) describes equal sharing or tit-for-tat exchange relationships, and market pricing (MP) involves the exchange of goods using assigned values.

Fiske’s work (2004) includes detailed accounts, supported by anthropological evidence across numerous cultures, of the types of embodied cues that are associated with each of these four relationship types. Specifically, CS relationships are said to be embodied by sharing substances such as food, physical closeness and touch, and synchronized bodily movements; AR relationships are embodied by differences in size or vertical position in space. It is valuable to think of these embodiment hypotheses in terms of Barsalou’s (1999) Perceptual Symbol System model, which holds that conceptual knowledge is represented by abstracted and generalized perceptual experiences that can be simulated (partially re-enacted) in context-sensitive ways. Barsalou’s model goes beyond the idea that we use bodily metaphors for types of social relationships, holding instead that perceptual experiences of physical closeness or synchrony or of differences in size or height partially constitute our concepts of relational closeness or differences in power or authority.

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Stigmergy and emergent behaviour

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This simulation from Jean Lievens.

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Science of Swarms

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A survey of swarming, a sub-topic of complexity. No mention of stigmergy though.

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The Dynamically Extended Mind – A Minimal Modeling Case Study

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This from Froese, Gershenson, and Rosenblueth.

The extended mind hypothesis has stimulated much interest in cognitive science. However, its core claim, i.e. that the process of cognition can extend beyond the brain via the body and into the environment, has been heavily criticized. A prominent critique of this claim holds that when some part of the world is coupled to a cognitive system this does not necessarily entail that the part is also constitutive of that cognitive system. This critique is known as the “coupling-constitution fallacy”. In this paper we respond to this reductionist challenge by using an evolutionary robotics approach to create a minimal model of two acoustically coupled agents. We demonstrate how the interaction process as a whole has properties that cannot be reduced to the contributions of the isolated agents. We also show that the neural dynamics of the coupled agents has formal properties that are inherently impossible for those neural networks in isolation. By keeping the complexity of the model to an absolute minimum, we are able to illustrate how the coupling-constitution fallacy is in fact based on an inadequate understanding of the constitutive role of nonlinear interactions in dynamical systems theory.

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Hayek

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Born on this day in 1899. It’s to analytical (social) epistemology’s (and philosophy of mind’s) impoverishment and shame that Hayek is not that well-known beyond the tiresome caricatures. For all my Hayekana see here. The featured image was very generously given to me by the highly exceptional Walt Weimer.

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Stigmergic dimensions of online creative interaction

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Extracts from Jimmy’s paper:

The web has experienced a recent proliferation of design expert communities in domains from software engineering (e.g. Sourceforge and Github) to art (DeviantArt and others). These communities have become hotbeds of creative interaction, with users posting their projects, closely interacting on new endeavors, and engaging in spirited discussion about their craft. With users in these communities constantly generating out new software, images, music and any other artifact imaginable, it is hard to deny that there is significant creative interaction happening. Members of these communities often possess widely varying degrees of proficiency, but more often than not, they have some baseline amount of talent that allows them to enter the community.

Enter Picbreeder. Picbreeder is a web-based system for collaborative interactive evolution of images. The Picbreeder applet starts by randomly generating several images, which are then mated and mutated based on the user’s selections. The user can then publish the image to the Picbreeder website where other users can download and continue the image’s evolution. Within Picbreeder, one need not have artistic talent to contribute to the community, although good taste typically helps. As in more traditional design, new innovations are typically small modifications to the existing structure, which can change the design incrementally or effect a larger shift. Even though users followed their individual interests when evolving this phylogeny, new interesting directions emerged. Many users contributed repeatedly to an evolving lineage, using the design itself to encourage and facilitate collaboration.

Successful collaborative design in Picbreeder does not require shared intentions, suggesting that effective collaboration may be emergent rather than planned from the top down. The surprising result of this emergent process is the gradual discovery by untrained users of hidden treasures within a vast uncharted space. Picbreeder also serves as a fascinating, though initially unintentional, experiment in stigmergic creativity.

The concept of stigmergy was first introduced by Pierre-Paul Grassé, a zoologist, who used it to describe the activities of the termite mound. As he described it, “(s)tigmergy manifests itself in the termite mound by the fact that the individual labour of each construction worker stimulates and guides the work of its neighbour”. The concept of stigmergy can be extended to human endeavors if one expands the notion of the mound to human venues, and replaces “construction worker” with any type of worker. If such an extension is permitted to human creative communities, this description becomes even more apt. Part of the excitement inherent in creative pursuits, whether it is visual art, music or creating open source software, is the moment when the work of a colleague “stimulates and guides” ones own work. Add that “(in) an insect society individuals work as if they were alone while their collective activities appear to be coordinated.” This description too can apply to creative communities. Points out that “(s)tudies on creativity . . . have focused on the individual, obscuring the fact that creativity is a collective affair. The ideas and inventions an individual produces build on the ideas of others (the ratchet effect).” It is very easy to focus on individual creative luminaries, while forgetting the environment and social milieu that are a large part of their creative interaction.

The results of Picbreeder not only demonstrate the truth of creativity as collaboration, but that a large component of creativity can be stigmergic. By abstracting out almost all direct communication and collaboration, and allowing users to be stimulated only by their work and the work of others, Picbreeder demonstrates the extent to which stigmergic processes can yield astounding results. This paper expounds on this point by first describing in detail what Picbreeder is and how it works (section 2). Next, the paper casts creativity in general and Picbreeder specifically into the context of memetic evolution, a model of how ideas spread, change, evolve and die out (section 3). The point is then made in section 4 that these collaborative creative environments draw a great deal of their effectiveness from stigmergic interaction facilitated through creative artifacts. In sections 5, an analysis of the Picbreeder data is described that shows, despite the fact that Picbreeder users engage in almost no direct communication, it shares numerous properties with other collaborative creative environments. Finally, some conclusions and recommendations are made in section 6.

This paper has shown that Picbreeder, an almost fully stigmergic means of collaborative creative interaction, follows many of the same patterns as other collaborative creative networks. Picbreeder demonstrates that it is possible to facilitate creative collaboration through entirely stigmergic means, and this paper explored the mechansisms that gave rise to that stigmergy. Because in other creative communities, stigmergic and non-stigmergic components of creative interaction are difficult to separate, Picbreeder provided an ideal opportunity to study this dimension. It is hoped that future studies will be able to isolate and study the contribution of stigmergic components in other creative communities.

It is also hoped that more quantitative analysis will be done on other creative communities. Academic publishing bibliometrics were used because they are plentiful and easy to access. While it is difficult to trace influence in similar way in musical or visual arts communities, developing techniques to analyze these communities is a worthwhile pursuit. This analysis may provide answers of real economic value. For instance, to answer the question, what will create a broader, more economically viable base of musical development, a U.S. style system in which music distribution is dominated by a few large gatekeepers to the music industry, or a Canadian style system which frequently uses government sponsored incentives to encourage development in musical communities?

There is a great deal of analysis left to be done and questions to be answered with respect to the dynamics of creative communities. For instance, how can Axelrod’s model of cultural diffusion (1997) explain creative influence? Also, how can Friedkin’s analysis of weak ties versus strong ones in organization flows (1982) inform the analysis of how creativity develops within and between organizations. Picbreeder is currently a “flat” community, which does not fully represent the wide variety of social creative arrangements. The addition of this dimension to analysis will hopefully yield additional insight.

Stigmergy is clearly involved in creativity. It is no accident that Silicon Valley is well known for technical innovation and Paris is a well known muse of artists. These physical locations host large collaborative and competent communities for one, but also frequently display and demonstrate the results of their interaction, to “stimulate and guide” other participants. Other creative communities might benefit by explicitly taking advantage of stigmergic concepts to improve their efficcacy. Imagine a paint studio where artists paint in a circle, with the paintings facing inward. Or a research lab where everybody’s latest work in progress is posted to a highly visible electronic board. The more we understand the role of stigmergy in creativity, the better we can shape and guide the process. Ultimately, every creative discipline, along with humanity itself, will be the beneficiaries of this advancement.

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Stigmergic self-organization and the improvisation of Ushahidi

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Here are some excerpts from Janet’s fascinating paper.

In late 2007 in Kenya, US educated Kenyan journalist Ory Okolloh had become one of the main sources of information about the election and the violence that broke out soon after. Because of the government‟s ban on live reporting and censorship of the mainstream media, Okolloh solicited information about incidents of violence from ordinary people in the form of comments posted on her personal blog. The mainstream media was not reporting on the violence because of the government ban, and Okolloh was quickly overwhelmed by the numbers of emails and messages that she received. In order to focus on the “immediate need to get the information out”, in early January Okolloh posted a request on her blog for help to develop a website where people could post anonymously online or via mobile phone text messages, the most accessible type of communications technology in Kenya. Within a day the Ushahidi („testimony‟ in Swahili) domain was registered and the website went live within less than a week. Built by 15-20 mainly Kenyan volunteers using open source software, the project was funded entirely by donations. Immediately, over 250 people began using the site to share information, even including radio stations. The process of report verification was simple. If the reporter could be identified, they were contacted for verification; if anonymous, a certain volume of similar reports was considered verification. Within weeks hundreds of incidents of violence had been documented in detail that would have otherwise gone unreported, and the website received hundred of thousands of site visits from around the world, sparking increased global media attention.

Following the events in Kenya, Humanity United, a non-profit organization dedicated to ending modern slavery and mass atrocities, offered to fund redevelopment of Ushahidi as a broadly available platform for collecting and visualizing information. In late 2008 the alpha version was released and tested in the Democratic Republic of Congo, among other places. The beta version, utilizing FrontlineSMS, free software that turns a laptop and a mobile phone or modem into a central communications hub, was released in 2009. The Frontline SMS software can be used on a single laptop computer without the need for the internet, allowing users to send and receive text messages with large groups of people through mobile phones. Since its original release in 2005, it has been widely adopted in the grassroots non-profit community and nominated for several awards [Banks]. Today, Ushahidi defines itself as “a non-profit tech company that develops free and open source software for information collection, visualization and interactive mapping” [http://ushahidi.com], and the development of Ushahidi has continued. Presently, there are three free downloads available: the Ushahidi platform, the Crowdmap application, and the SwiftRiver application. In 2008, Ory Okollah said, “We anticipate that the platform will revolutionize how many organizations handle their data and also democratize how information is collected and shared in crisis situations” and characterized the Ushahidi development strategy as: “pushing the boundaries of Rapid Prototype Model, Crowdsourcing, Visualization, Mapping, and Mobile Phone Platforms.”

A study of the evolution of the Ushahidi software presents strong evidence of cognitive stigmergy at two levels. The first level is the development of the Ushahidi platform, both initially and through the creation of the enhancements. The development of the software using a Rapid Prototype model and crowdsourcing on widely available mobile phone platforms follows examples of some FLOSS development teams that have been shown to use cognitive stigmergy as a tool to organize and coordinate work. The utilization of the software by end users as volunteers and contributors also demonstrates the role of cognitive stigmergy at the level of group action. The occurrences of crowdsourcing demonstrate cognitive stigmergy. The reasons for the great success of Ushahidi lie precisely in its raison d‟etre: it was conceived as a way for people to give testimony to the world about a great crisis that was occurring. Ushahidi was meant to empower, to give voice, and was specifically designed to do so for all. Heylighen points out that the inexpensive cost of information via the internet is a major force for the increase in all forms of information, easy access to it and voluntary creation and sharing of forms of it. The combination of easy access, low cost, and a compelling social concern lead to powerful motivations for many to participate. The use of the Rapid Prototype Model meant that the functionality could be delivered while there was still an urgent need for it, before the crisis could pass and life returned to normal and that urgency was forgotten. The use of Visualization and Mapping was crucial. Human cognitive stigmergy is based on people perceiving changes in their environment and responding to them. Visual images and information are more meaningful even when the place is not known, even more powerful when it is. Testimony has more power when it is visualized. The dependence on Crowdsourcing as a resource for development, support and the generation of information is an obvious example of stigmergic self-organization. As a way to maximize participation and crowdsourcing, the use of Mobile Phone Platforms via FrontlineSMS is a clear success: “In Africa, cellphone penetration – the number of phones as a percentage of the population – is still the lowest in the world, but it is growing quickly. In 2010, an estimated 41 per cent of the population on the continent had cellphones, compared with 76 per cent globally. That’s double what it was in 2005”. Worldwide, it is estimated that there are five billion mobile phones in use as of 2010, and for many users, these are the only access they have to computing or telecommunications capability.

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Stigmergy in human practice: Coordination in construction work

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Some excerpts from Lars’ paper.

When the concept of stigmergy was first introduced in 1959 by the French entomologist Pierre-Paul Grassé (1959), an important step towards understanding the coordination of collective activities in social insects was made. Today, the concept of stigmergy is well established within the field of entomology (Theraulaz and Bonabeau, 1999). Turning from the study of insect behaviour to the study of human practice we find the concept of stigmergy to be less well established. However, criteria for applying the concept of stigmergy to the study of human practice are in fact readily emerging and a series of interesting and illuminating studies of stigmergy in a human context has been published (e.g. Christensen, 2008; Marsh & Onof, 2008; Ricci et al., 2007; Susi & Ziemke, 2001; Tummolini & Castelfrananchi, 2007; Parunak, 2006). This paper aims to contribute to this body of literature. Building on Grassé (1959), we will argue that that a coordinative effect can occur when human individuals act on the physical traces of work accomplished previously by others. That is, we will say that actors may coordinate and integrate their cooperative efforts by acting directly on the physical traces of work previously accomplished by others and that signs left or modifications made by individuals on artifacts may, given an appropriate context of practice, become meaningful to others and in turn inspire new actions on artifacts. This is how stigmergy may unfold in a human context. However, in connection to the study of stigmergy in a human context we need to ask a fundamental question before we “get ahead of ourselves.” The question is this: Does the concept of stigmergy add anything to our ability to account for the coordination of cooperative work in a human context? After all, stigmergy is a concept of coordination (Theraulaz and Bonabeau, 1999) and if we are to apply it to the study of human practice we have to ensure that it is not redundant in this context. That is, we have to make sure that there are no other concepts of coordination already having the analytical role that we are casting for the concept of stigmergy. This work has not been done so far (see related work section), and we shall address this challenge here. We shall proceed in the following manner. First we shall discuss related work. Secondly, we shall establish the nature of the concept of stigmergy in the study of human practice. Third, we shall compare the concept of stigmergy to three well-established concept of coordination in order to satisfy ourselves that stigmergy is not interchangeable with them. Fourth, we shall employ the concept of stigmergy in a study of construction work in order to explore the analytical utility of the concept in a human context. Finally, a conclusion and some perspectives will be offered.

In construction work, as in building design (Christensen, 2007; 2008), interdependent tasks may be partly integrated by virtue of individuals paying heed to the material evidence of work previously accomplished by others while performing their own tasks. Cooperative construction work tasks may be integrated through practices of stigmergy. As a case in point we shall consider the integration of cooperative work tasks pertaining to the construction of interior walls in a large building project. In the interior construction stage of a large building project a considerable number of partition walls are constructed. Partition walls are what divide the building into for instance units of office space. The construction of these walls is a cooperative work process involving a number of different trades such as carpenters, electricians and painters (see figure 2). The first and second frame shows the result of the carpenter’s initial efforts. The third frame, including insert, shows the work of the electrician in progress. Finally, the fourth frame depicts the closed wall ready for painting. The initial parts of a partition wall is constructed by a carpenter in the form of a frame made of light weight steel grinders fitted with plasterboards on the one side. At a later point in time, another actor, namely, an electrician will arrive and pay heed to the work carried out and seek to align the wiring of the electrical circuits with it. That is, the electrician will drill holes in the plasterboard to accommodate the electrical instillations and he or she will pull electrical cables through little holes in the vertical steel grinders of the frame and connect them to the electrical system as a whole. When the electrician is done and has left the scene, the carpenter returns to close the wall i.e. clad the second side of the wall in plasterboards in accordance with the previous work done. That is, the carpenter must take notice of the work previously performed by himself and the electrician as he seeks to put up the second round of plasterboards. Subsequently, the painter shows up to paint what the others have erected. At this point the wall in-the-making will have been worked on to consist of a steel frame, plasterboards on the first side, electrical instillations inside, and plasterboards on the second side. Finding the wall in this state the painter paints the wall with several coats of paint. In this manner the work ensemble including carpenter, electrician and painter all make distinct contributions towards the construction of the wall in accordance with their respective areas of expertise. We could say that the individual actor creates and changes the form of the wall in-the-making, not for the purpose of conveying a message, but simply as part of performing their individually allotted tasks, in turn another actor pays heed to and acts upon the material evidence of the work of others. This is partly how the cooperative work tasks pertaining to the construction of partition walls are integrated through practice of stigmergy. Perhaps to allow for full appreciation of the importance of this mode of coordination in building construction work, it would prudent to recall that no formal construct (e.g. architectural plan) exhaustively stipulates a concrete practice. Plans are underspecified with respect to that which is represented (Suchman, 1987), and architectural plans for the construction of for example partition walls are no exception. The actors have to “fill in the blanks” for themselves, so to speak, and acting on the evidence of work previously accomplished by others may be said to be one way of doing this. Furthermore, please bear in mind that architectural plans for specific building parts such as walls are not assembly manuals like those that come with for example IKEA furniture, rather architectural plans represent mainly how parts of the building it are supposed to look in the final state. Consequently, the assembly of for example partition walls is not covered in architectural plans. In addition, the pace of contemporary construction work is such that as soon as one actor (e. g. carpenter) has completed a task, time does not allow for much standing around and talking to the next actor (e. g. electrician) even though their tasks are interdependent and there are numerous details that need to be integrated. Of course articulation work through talk on the building site or in weekly coordination meetings may contribute to the integration of cooperative construction work tasks, but so may acting on the material evidence of work previously accomplished. The point is that in addition to various kinds of articulation work in meetings and with and without coordinative artifacts such as time schedules, cooperative construction work is coordinated by virtue of actors paying heed to the material evidence of work previously accomplished by others while performing their own tasks. At this juncture we may ask if the physical “evidence” of work may be promoted by the way in which the work is performed making it more straightforward for others to act on in practice of stigmergy? With reference to our case above, we may say that an electrician could for example install the electrical wiring and let a cable hang conspicuously visible in order to make the carpenter pay heed to it and afford it the required space as the wall is closed with the second layer of plasterboards (if the cables are completely hidden to the carpenters view he or she may accidentally put a nail through it with the nail gun as the second layer of plasterboards are mounted on the frame of the wall). This raises an interesting point: coordination through the material field of work may also be a matter of being mindful of the work that is to be performed by others looking forward in time, rather than only a matter of paying heed to work previously accomplished by others. At this point we may remind ourselves “the economy of logic […] dictates that no more logic is mobilized than is required by the needs of practice” (Bourdieu, 1992, p. 145). Following Bourdieu, we may say that the individual actors will engage in no more physical and cognitive effort than is practically necessary. That is, unless an actor has practical reasons for considering the situation from the perspective of others such as for example subsequent actors that may follow in practices of stigmergy, he or she will retain his or her own perspective and just carry out the work without though for the perspectives of others. Note that it is of course an empirical matter, something that differs from case to case, exactly how this plays out in practice. It is important to note that stigmergy, as a coordinative practice, is in not dependant on such forward looking mindfulness although it may be part of the larger set of practices. In sum, in construction work, cooperative work tasks are (partly) integrated through practices of stigmergy.

The concept of stigmergy was not originally developed in order to describe human practice, rather it was developed within the field of entomology i. e. the study of social insects. This study has raised and addressed a question central to any attempt to introduce the concept of stigmergy to the study of human practice: Does the concept of stigmergy add anything to our ability to account for the coordination of human cooperative work or is it simply interchangeable to already existing concepts? We have argued that it does add a new analytical perspective. Initially we suggested that in the context of human practice it is fruitful to understand stigmergy as a “heed” concept. That is, stigmergy refers to the phenomenon that distributed cooperative work tasks may be partly integrated by virtue of individuals paying heed to the material evidence of work previously accomplished by others while performing their own tasks. Based on this understanding of the concept of stigmergy in the context of human practice we explicitly compared and delimited the concept in relation to well-established concept describing human coordinative practices. We found that it differs from these concepts. We found that the concept of stigmergy is not interchangeable to well-established concepts of coordination such as articulation work, awareness and feedthrough. Finally, we explored the potential of the concept of stigmergy in an empirical study of coordinative practice in construction work in order to further investigate the utility of the notion of stigmergy as an analytical tool in the context of human practice. In regard to perspectives for further research, we may note that the three concepts of stigmergy, articulation work and awareness could amount to a trinity in the analytical toolbox for the description and analysis of the coordination of cooperative work – each concept pertaining to a unique yet interconnected mode of coordination of cooperative work.

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Emergence in stigmergic and complex adaptive systems: A formal discrete event systems perspective

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Some extracts from Saurabh Mittal’s paper.

A natural system is not a monolithic system but a heterogeneous system made up of disparity and dissimilarity, devoid of any larger goal. The system just “is.” Examples of such systems include ant colonies, the biosphere, the brain, the immune system, the biological cell, businesses, communities, social systems, stock markets etc. Such systems are adaptable systems where emergence and self-organization are factors that aid evolution. These systems are classified as complex adaptive systems. According to Holland (2006, 1): “CAS are systems that have a large number of components, often called agents that interact and adapt or learn.”

In this article, we investigate CAS by looking at the scale of components, interactions between the components, and emergent properties that are manifested by such CAS. We will attempt to understand some of the common underlying properties, address the adaptive nature of such complex systems and illustrate how resilience is an inherent property of CAS.

CAS is occasionally modeled by means of agent-based models and complex network-based models. Multi-agent systems (MAS) is the area of research that deals with such study. However, CAS is fundamentally different from MAS in portraying features like self-similarity (scale-free), complexity, emergence and self-organization that are at a level above the interacting agents. A CAS is a complex, scale-free collectivity of interacting adaptive agents, characterized by high degree of adaptive capacity, giving them resilience in the face of perturbation. Indeed, designing an artificial CAS requires formal attention to these specific features. We will address these features and the formalisms needed to model CAS.

The discipline of modeling originated to understand natural phenomena. By developing abstractions, we can manage the apparent complexity, reuse it and enable these complex phenomena in artificial systems to our advantage. The discipline of executing this model on a time base is “simulation.” The task of decoding the original structure from manifested behavior is the holy grail of the modeling and simulation (M & S) enterprise (Zeigler, Praehofer, & Kim, 2000). The need for M & S to make progress in understanding CAS has been well acknowledged by Holland (1992). The task is to understand the gamut of rules that exist within and without a component and understand how the component deals with such multidimensional rules in an interactive environment. M & S is the only way one can understand, mimic and recreate a natural system. Most artificially modeled systems that exhibit complex adaptive behavior are driven by multi-resolution bindings and interconnectivity at every level of system behavior. To understand life is to “model”; to adapt is to survive in an environment, where both survival and environment are loaded concepts based on the guiding discipline.

Complexity is a phenomenon that is multivariable and multi-dimensional in a space-time continuum. Therefore, what we need is a framework that helps develop system structure and behavior in an abstract manner and that is component oriented so that the system can define its interactions based on the composition of a multi-level environment.

Stigmergy, the study of indirect interaction between network components in a persistent environment, explains certain emergent properties of a system. The network components include both the environment and the agent and both are persistent, i.e. both are situated in a space-time continuum and have memory. We take Stigmergic systems to be a subset of CAS and argue that stigmergic behavior is an emergent phenomenon too. Ultimately, we are trying to get a handle on how to formalize the property of “emergence.”

Discrete event abstraction has been studied at length by Bernard Zeigler throughout his illustrious career and his pioneering work on Discrete Event Systems (DEVS) formalism in 1970s (Ziegler, 1976). As a student, his perspectives on CAS were influenced by Holland. Ziegler’s approach to CAS has been through the quantization of continuous phenomena and how quantization leads to abstraction. Any CAS must operate within the constraints imposed by space, time, and resources on its information processing (Pinker, 1997). Evidence from neuronal models and neuron processing architectures and from fast and frugal heuristics, provide further support to the centrality of discrete event abstraction in modeling CAS when the constraints of space, time and energy are taken into account. Zeigler stated that discrete event models are the right abstraction for capturing CAS structure and behavior (Zeigler, 2004). In this article, we take the discipline of modeling CAS forward, by looking at the emergence aspect of CAS. We introduce DEVS and demonstrate how recent extensions still fall a little short in modeling CAS.

We first focus on the study of network science and how scale-free networks are inherently important to study complex interactions and hierarchical systems. In Section 3 we look at various types of interactions in a complex network. Section 4 we address the concepts of emergence and self-organization in detail and examine how a complex dynamic network facilitates such behavior. Section 5, a slight digression, provides an overview of DEVS theory. We return to the subject of dynamism in a complex adaptive network in Section 6 and show how DEVS theory is positioned to give modeling and simulation support to the subject. We describe various existing formal DEVS extensions that help model various features of stigmergy, emergence and CAS. Finally, in Section 7, we present some conclusions and pointers for future research.

Complexity is a multifaceted topic and each complex system has its own properties. However, some of the properties like high interconnectedness, large number of components, and adaptive behavior are present in most natural complex systems. We looked at the mechanism behind interconnectedness using network science that describes many natural systems in the light of power laws and self-similar scale-free topologies. Such scale-free topologies bring their own inherent properties to the complex system such that the entire system is subjected to the network’s structural and functional affordances.

It is largely unknown what makes a network evolve into a scale-free network, whether it is a top-down goal-driven phenomena or bottom-up causation or just an outcome of natural interactions. Two conditions have to be present for a network to evolve into a scale-free network: 1. incremental growth and 2. preferential attachment. We explored the notions of scale-free nature, strong and weak emergence, self-organization and stigmergic behavior in a complex adaptive system with persistent agents and persistent environment. We also related the concept of emergence to network science and presented arguments on how hubs and connectors are formed when a complex system is going through a critical phase. We argued that under any occurrence of both self-organized and emergent behavior together, the properties of scale-free network exist and one has to look at right level of abstraction in a multi-level system to witness the instance based interactions. We established that stigmergy displays strong emergence and is a specialized case of CAS. We also enumerated 18 properties of a CAS, 11 of which were properties of stigmergic systems.

We presented a high level view of DEVS theory and how its formal rigor is able to specify complex hierarchical systems. We described variants of dynamic structure and multi-level DEVS, and mapped it to some of the identified properties of CAS and stigmergy. We detailed the adaptive nature of complex system with DEVS Level of system specification and what it means to have dynamic adaptive behavior at different levels of a system. During the mapping process, we found that the following capabilities warrant formal attention to extend DEVS theory of complex systems to a theory of complex adaptive systems:

  1. How clusters are formed, hubs appear and evolve.
  2. How multi-level self-organization occurs.
  3. How strong emergence results in self-organization with an embedded observer capable of causal behavior at lower levels of hierarchy.
  4. How formal attention to coupling specification may provide additional abstraction mechanisms to model dynamic interconnected environment.

Finally, we recommended the augmentation of as the foundation for Stigmergic-DEVS, and investigation of both and ML-DEVS augmented together as a foundation for CAS-DEVS.

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Cognitive stigmergy: A study of emergence in small-group social networks

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This paper proposes a model and theory of leadership emergence whereby (1) small social groups are modeled as small world networks and a betweeness metric is shown to be a property of networks with strong leadership, and (2) a theory of group formation based on stigmergy explains how such networks evolve and form. Specifically, dominant actors are observed to emerge from simulations of artificial termites constructing a wood chip network in a random walk, suggesting a correlation between various preferential attachment rules and emergent network topologies. Three attachment rules are studied: maximizing node betweeness (intermediary power), maximizing node degree (node connectivity), and limiting radius (size of the network in terms of network distance). The simulation results suggest that a preference for maximizing betweeness produces networks with structure similar to the 62-node 9-11 terrorist network. Further simulations of emergent networks with small world properties (small radius) and high betweeness centrality (strong leader) are shown to match the topological structure of the 9-11 terrorist network, also. Interestingly, the same properties are not found in a small sampling of human made physical infrastructure networks such as power grids, transportation systems, water and pipeline networks, suggesting a difference between social network emergence and physical infrastructure emergence. Additionally, a contagion model is applied to random and structured networks to understand the dynamics of anti-leader sentiment (uprisings and counter-movements that challenge the status quo). For random networks, simulated pro-leader (pro-government) and anti-leader (pro-rebel) sentiments are propagated throughout a social network like opposing diseases to determine which sentiment eventually prevails. Simulations of the rise of rebel sentiment versus the ratio of rebel to government sentiment show that rebel sentiment rises on less than 100% rebel/government sentiment when government sentiment is high (strong leadership), but requires greater than 100% rebel/government sentiment when government sentiment is low (weak leadership). However, when applied to the structured 9-11 terrorist network, rebel sentiment is slow to rise against strong leadership, because of the high betweeness structure of the 9-11 network. These results suggest a theory of how and why human stigmergy evolves networks with strong leaders, and why successful social networks are resilient against anti-leader sentiment. The author concludes that a combination of small world and high betweeness structure explain how social networks emerge strong leadership structure and why the resulting networks are resilient against being overthrown by a dissenting majority.

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